PE Pipe - Design and Installation

168 Pages·2006·19.949 MB·English

PE Pipe - Design
and Installation
MANUAL OF WATER SUPPLY PRACTICES M55, First Edition
AWWA MANUAL M55
First Edition
American Water Works
Association
Science and Technology
AWWA unites the drinking water community by developing and distributing authoritative scientific and technological
knowledge. Through its members, AWWA develops industry standards for products and processes that advance public
health and safety. AWWA also provides quality improvement programs for water and wastewater utilities.
Copyright (C) 2006 American Water Works Association All Rights Reserved
MANUAL OF WATER SUPPLY PRACTICES-M55, First Edition
PE Pipe-Design and Installation
Copyright Q 2006 American Water Works Association
All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any
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content or any consequences of their use. In no event will AWWA be liable for direct, indirect, special,
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Project ManagerKopy Editor: Melissa Christensen
Production: Glacier Publishing Services, Inc.
Manuals Coordinator: Beth Behner
Library of Congress Cataloging-in-PublicationD ata
PE pipe : design and installation.-- 1st ed.
p. cm.
Includes bibliographical references and index.
ISBN 1-58321-387-2
1. Pipe, Plastic Design and Construction. 2. Polyethylene.
TA448.P4 2005
628.1'5-dc22
2005055888
Printed in the United States of America.
American Water Works Association
6666 West Quincy Avenue
Denver, CO 80235-3098
ISBN 1-58321-387-2
Printed on recycled paper
Copyright (C) 2006 American Water Works Association All Rights Reserved
Figures
1-1 Traditional model of HDPE, 4
1-2 Generalized tensile stress-strain curve for PE pipe grades, 6
2-1 Typical extrusion line, 23
2-2 Typical pipe extruder, 23
2-3 Typical injection molding machine, 24
2-4 Prefabricated 90" elbow being attached in field, 24
3- 1 Moody diagram, 35
5-1 AASHTO HS20 wheel load distribution, 52
5-2 Load distribution over buried pipe, 55
5-3 Ovality correction factor, 64
6- 1 Butt fusion joint, 75
6-2 Typical butt fusion machine (butt fusion machines are available to fuse pipe up
to 65 in. in diameter), 75
6-3 Conventional saddle fusion joint, 77
6-4 Typical electrofusion saddle fusion, 77
6-5 Socket fusion joining, 79
6-6 Typical electrofusion joint, 79
6-7 Typical electrofusion fitting and control box (lower right), 79
6-8 Mechanical compression coupling with restraint-PE restrained by
electrofusion flex restraints-PVC pipe restrained using a tapered gripping
ring, 81
6-9 PE flange adapter, 82
6-10 Mechanical flange adapter, 85
6-11 MJ adapter, 85
6-12 Transition fittings, 86
6-13 Molded and fabricated elbows, 86
6-14 Electrofusion branch saddle connected to gate valve by MJ adapters, 87
6-15 Conventional saddle fusion branch saddles, 87
6-16 Mechanical tapping saddle, 88
6-17 Saddle tapping tees, 88
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Copyright (C) 2006 American Water Works Association All Rights Reserved
6-18 High volume tapping tees (HVTT), 89
6-19 Corporation stop saddles, 89
7- 1 Typical silo pack truckload (40-ft trailer), 93
7-2 Typical bulk pack truckload (40-ft trailer), 93
7-3 Typical strip load truckload (40-ft trailer), 93
7-4 Forklift load capacity, 95
7-5 Loose pipe storage, 97
8-1 Trench construction and terminology, 101
8-2 Trench width, 104
8-3 Trench box installation, 104
8-4 Bend radius, 106
8-5 Example haunch tamping tool, 108
8-6 Pullout prevention technique, 109
8-7 Pullout prevention technique, 109
8-8 In-line anchor using flex restraint, 110
8-9 In-line anchor using integral pipe collar (wall anchor), 110
8-10 Controlling shear and bending, 112
8-11 Flange support at wall, 112
8-12 Appurtenance support pad, 112
8-13 Split backup ring, 117
8-14 Concrete weight, 122
8-15 Concrete weight, 122
8-16 Flotation above the surface, 122
8-17 Flotation at the surface, 122
8-1 8 Deflection between floats, 124
8-19 Float submergence, 125
10-1 Damage to PE pipe by backhoe bucket, 135
10-2 Wrap-around repair sleeve used to repair small puncture holes in PE pipe, 135
10-3 Electrofusion saddles are available for repairs, 135
10-4 Repair using self-restraining mechanical couplings, 137
10-5 Bolted, sleeve-type coupling, 137
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Copyright (C) 2006 American Water Works Association All Rights Reserved
10-6 Insert stiffener, 137
10-7 Repair using electrofusion couplings, 137
10-8 Section replacement using flanged spool, 137
10-9 Section replacement by deflecting smaller pipes, 137
10-10 Damage to saddle by backhoe, 138
10-11 Threaded outlet repair saddle, 138
10-12 90" ell compression fitting, 138
10-13 Straight coupling, 138
10-14 Male adapter, 138
10-15 Reducing coupling, 138
10-16 Attachment of mechanical saddle, 139
10-17 Corp stop attached to mechanical saddle, 139
10-18 Electrofusion saddle, processor, corp stop, adapters, wrench, and cutter for hot
tap, 139
10-19 Electrofusion saddle with corp stop and cutter attached through corp stop to
make hot tap, 140
10-20 A 6-in. outlet saddle with MJ adapter for fusion on 8-in. PE pipe, 140
10-21 Electrofusion coupling connecting PE reducing tee with mechanical joint
adapter to PE pipeline, 141
10-22 In-the-trench sidewall fusion to attach saddle to water line, 141
10-23 Tapping sleeve with MJ outlet, 141
10-24 Compression by flange coupling for use in joining PE to other materials, 141
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Copyright (C) 2006 American Water Works Association All Rights Reserved
Tables
1-1 Effects of density, molecular weight, and molecular weight distribution, 2
1-2 Electrical properties of PE, 9
1-3 ASTM D3350 cell classification limits, 16
1-4 Example of D3350 cell class specification, 16
3-1 PE 3408 polyethylene pipe iron pipe size (IPS) pipe data, 32
3-2 PE 3408 polyethylene pipe ductile iron pipe size (DIPS) pipe data, 34
3-3 Representative equivalent length in pipe diameters of various piping
components, 37
4-1 Hydrostatic design basis (HDB)f or standard PE 3408 and PE 2406
materials, 40
4-2 Pressure class for PE 3408 and PE 2406 pipe, 42
4-3 Surge pressures generated by a sudden change in water flow velocity for PE
pipes operating at service temperatures through 80°F (27"C),4 4
4-4 Pressure class, surge allowance, and corresponding sudden velocity change for
PE 3408 pipe operating at service temperatures through 80°F (27"C),4 5
4-5 Pressure class, surge allowance, and corresponding sudden velocity change for
PE 2406 pipe operating at service temperatures through 80°F (27"C),45
4-6 Temperature compensation multipliers, FT, 47
4-7 PE 3408 working pressure rating for recurring surge events as a result of
instantaneous change in water column velocity, 47
5-1 Impact factors for paved road, 52
5-2 H20 loading (rigid pavement), 53
5-3 AASHTO H20 loading under flexible pavement and unpaved roads, 53
5-4 Cooper E-80 railroad loads, 55
5-5 Influence coefficients, 56
5-6 Apparent modulus of elasticity 63 73"F,5 8
5-7 Bureau of Reclamation values for E,m odulus of soil reaction, 59
5-8 Duncan-Hartley's values of E', modulus of soil reaction, 60
5-9 Values of EN,m odulus of soil reaction for native soil, from Howard, 61
5-10 Soil support factor, S,, 61
5-11 Design deflection for pressure pipe, 62
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Copyright (C) 2006 American Water Works Association All Rights Reserved
6- 1 Approximate joining rates for butt fusion, 76
7-1 Suggested jobsite loose storage stacking heights for conventionally extruded
pipe lengths, 97
8-1 Minimum trench width, 104
8-2 Minimum cold (field) bending radius (long-term), 106
8-3 Embedment soil classification, 107
8-4 Approximate Poisson effect pullout force, 111
8-5 Recommended design factors, 115
8-6 Approximate tensile yield strength values, 115
8-7 Minimum short-term bending radius, 115
8-8 Underwater environment factor, K,, 119
8-9 Specific gravities and specific weights at 60°F (15"C), 119
8-10 Pipe weight conversion factors, 120
8-11 Approximate ballast weight spacing, 121
8-12 Polyethylene float properties, 125
8-13 Submergence factor, fs, 125
9- 1 Standard pressure class, 129
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Copyright (C) 2006 American Water Works Association All Rights Reserved
Terms and Equation Symbols
Term or
Symbol Meaning
a wave velocity (celerity), fWsec
A wheel contact area, in.2
ATL allowable tensile load, lb
B float buoyancy, Iblft
B' soil elastic support factor
Bd trench width at the pipe springline, in.
BN negative buoyancy, lblft
BP buoyancy of pipe, lblft
C Hazen-Williams flow coefficient, dimensionless
D average inside pipe diameter, ft
d float outside diameter, in.
DF design factor, dimensionless - the factor that is used to reduce the hydrostatic
design basis to arrive at the hydrostatic design stress from which the pressure
class is determined. Unless otherwise noted, the design factor for water
applications is 0.5
Di average inside pipe diameter, in.
DIPS ductile iron pipe size - the nominal outside diameter is the same as ductile iron
Pipe
DM mean diameter, in. (Do - t)
Do average outside diameter of the pipe, in.
DR dimension ratio (dimensionless) - the ratio of the average specified outside
diameter to the specified minimum wall thickness (DJt) for outside diameter
controlled polyethylene pipe
E apparent modulus of elasticity for pipe material, psi
e natural log base number, 2.71828
E' design modulus of soil reaction, psi
Ed dynamic instantaneous effective modulus of elasticity of the pipe material, psi
(150,000 psi for polyethylene)
E'E modulus of soil reaction of embedment soil, psi
E" modulus of soil reaction of native soil, psi
f Darcy-Weisbach fraction factor, dimensionless
F pullout force, lb
ovality compensation factor
f0
fSA actual float submergence factor
FT temperature compensation multiplier, dimensionless
tensile yield design (safety) factor
fT
time under tension design (safety) factor
fY
g acceleration due to gravity, 32.2 fWsec2
H soil height above pipe crown, ft
h float submergence below water level, in.
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Copyright (C) 2006 American Water Works Association All Rights Reserved
Term or
Symbol Meaning
HDB hydrostatic design basis, psi - the categorized long-term strength in the
circumferential or hoop direction for the polyethylene material as established
from long-term pressure tests in accordance with PPI TR-3 and the methodology
contained in ASTM D2837
HDS hydrostatic design stress, psi - the hydrostatic design basis multiplied by the
design factor (HDB x DF)
hf frictional head loss, ft of liquid
HOT depth of open trench, ft
Hw groundwater height above pipe, ft
I moment of inertia, in.4
IC influence coefficient, dimensionless
-
IDR inside dimension ratio, dimensionless the ratio of the average specified inside
diameter to the specified minimum wall thickness (D/t) for inside diameter
controlled polyethylene pipe
If impact factor, dimensionless
IPS iron pipe size - the nominal outside diameter is the same as iron (steel) pipe
K bulk modulus of liquid at working temperature (300,000 psi for water at 73°F
[23"C1)
K, underwater environment factor
L length of pipe, ft
LBS ballast weight spacing, ft
Le, equivalent length of straight pipe, ft - for fittings, the equivalent length of
straight pipe that has the same frictional head loss as the fitting
LF length of float, ft
LOT length of open trench, ft
LS distance between supports, ft
length of supported pipeline, ft
LSP
Lt time-lag factor, dimensionless
MM density of foam fill, lWft3
N safety factor
P pipe internal pressure, psi
maximum allowable system pressure during occasional surge, psi
P(MAX)(OS)
maximum allowable system pressure during recurrent surge, psi
P(MAX)(RS)
PC pressure class, psi - the pressure class is the design capacity to resist working
pressure up to 80°F (27°C) with specified maximum allowances for recurring
positive pressure surges above working pressure. Pressure class also denotes
the pipe's maximum working pressure rating for water at 80°F (27°C)
PCA allowable external pressure for constrained pipe, psi
PE polyethylene
PE earth pressure on pipe, psi
PE 2406 a standard code designation for polyethylene pipe and fittings materials that
has a minimum cell classification of 213333C, D, or E per ASTM D3350 and a
hydrostatic design basis at 73.4"F( 23°C) of 1250 psi
PE 3408 a standard code designation for polyethylene pipe and fittings materials that
has a minimum cell classification of 334434C, D, or E per ASTM D3350 and a
hydrostatic design basis at 73.4"F( 23°C) of 1600 psi
surcharge earth load pressure at point on pipe crown, psf
PES
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Copyright (C) 2006 American Water Works Association All Rights Reserved
Term or
Symbol Meaning
PL vertical stress acting on pipe crown, psi
Pos pressure allowance for occasional surge pressure, psi - occasional surge
pressures are caused by emergency operations that are usually the result of a
malfunction such as power failure or system component failure, which includes
pump seize-up, valve stem failure, and pressure-relief-valve failure
PRS pressure allowance for recurring surge pressure, psi - recurring surge pressures
occur frequently and inherent in the design and operation of the system (such as
normal pump startup and shutdown and normal valve opening or closure)
Ps transient surge pressure, psi - the maximum hydraulic transient pressure
increase (water hammer) in excess of the operating pressure that is anticipated
in the system as a result of sudden changes in the velocity of the water column
PUA allowable external pressure for unconstrained pipe, psi
Pv negative internal pressure (vacuum) in pipe, psi
Q volumetric liquid flow rate, U.S. gallmin
R equivalent radius, ft
Rb buoyancy reduction factor
Re Reynolds Number, dimensionless
S hydraulic slope, ftJft - frictional head loss per foot of pipe (hf/L)
S hoop compressive wall stress, psi
sc soil support factor
SDR standard dimension ratio (dimensionless) -the ratio of the average specified
outside diameter to the specified minimum wall thickness for outside diameter
controlled polyethylene pipe, the value of which is derived by adding one to the
pertinent number selected from the ANSI Preferred Number Series R10. Some
of the values are as follows:
R10 SDR
5 6
6.3 7.3
8 9
10 11
12.5 13.5
16 17
20 21
25 26
31.5 32.5
40 41
SL specific gravity of liquid
SP internal pressure hoop stress, psi
t minimum specified wall thickness, in.
average wall thickness, in. - 106%o f minimum wall thickness (t"1.06)
ta
TY pipe tensile yield strength, psi
V average velocity of flowing fluid, ftJsec
VB pipe bore volume, ft3/ft
VF float internal volume, ft3/ft
VP displaced volume of pipe, ft3/ft
W unit weight of soil, lb/ft3
W supported load, lb
WBD weight of dry ballast, lb/ft
WBS weight of submerged ballast, lb/ft
Copyright (C) 2006 American Water Works Association All Rights Reserved